1. Field
Exemplary embodiments of the present invention relate to a method for a semiconductor device, and more particularly, to a semiconductor device including an epitaxial layer and a fabrication method thereof.
2. Description of the Related Art
An integrated circuit (ICs) includes a transistor such as MOSFET. As the integrated circuit is scaled down, it is difficult to maintain or improve performance of the transistor. One of methods for improving performance of a transistor is to apply stress to a channel region of the transistor.
When suitable stress is applied to a channel region of a transistor, mobility of carriers in the channel region increases. When compressive stress is applied to a channel region of a PMOS transistor, mobility of holes in the channel region increases. In addition, when tensile stress is applied to a channel region of an NMOS transistor, mobility of electrons in the channel region increases.